For a conventional permanent magnetic separator or separating system, permanent magnetic materials are generally inserted in the outer surface of a drum or roller, and substances with different specific susceptibilities are separated by using the energy generated on the outer surface thereof. Moreover, there are two feeding modes, i.e., feeding on the outer surface of a permanent magnetic drum and feeding under the outer surface of a permanent magnetic drum. In the mode of feeding on the outer surface of a permanent magnetic drum, materials to be selected can contact directly with the magnetic surface, the residence time of the materials to be selected on the magnetic outer surface is short, the adsorptive capacity is large, but the separation effect will be effected, thus in such a mode, the yield may be increased, but the separation effect will be poor; in the mode of feeding under the outer surface of a permanent magnetic drum, there is a certain gap between the materials to be selected and the magnetic outer surface, the separation effect is good, but the yield is low, and greater object product will be run off.
In the traditional separation of materials to be selected, the stripping off of a high magnetic material is realized by a scraper or brush roller, or a magnetic material is partially inserted in the permanent magnetic drum or roller, and when the drum or roller rotates to an area without magnetic materials, the high magnetic material is flushed with water and falls into a high magnetic material groove or silo; for a conventional separator or separating system, the included angle between the whole system and the plane is nonadjustable, and its capacity for treating the materials to be selected is poor and the residence time of the materials to be selected on the permanent magnetic drum or roller is short; the surface field strength and gradient of the conventional permanent magnetic separator or separating system is a fixed value, thus the range of materials to be selected by a conventional permanent magnetic separator or separating system and the capacity of the conventional permanent magnetic separator or separating system is very limited.